html,
*{
    margin: 0;
    padding: 0
}
body {
    margin: 0;
    height: 100%;
    font-size: 62.5%;
}

.m-header {
    position: fixed;
    top: 0;
    left: 0;
    /*z-index大的元素会覆盖z-index小的元素*/
    z-index: 2;
    width: 100%;
    height: 60px;
    color: white;
    background-color: cornflowerblue;
}
.i-header {
    position: fixed;
    top: 0;
    left: 0;
    /*z-index大的元素会覆盖z-index小的元素*/
    z-index: 2;
    width: 100%;
    height: 100px;
    color: white;
    background-color: cornflowerblue;
}

.side-bar {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1;
    width: 200px;
    height: 100%;
    padding-top: 90px;
    background-color: black;
}

.page-board {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    padding: 90px 30px 30px 230px;
}

a {
    color: white;
    text-decoration: none;
}

.h-a {
    display: inline-block;
}
.m-l-10{
    margin-left: 10px;
}
.m-l-20{
    margin-left: 20px;
}
.m-t-10{
    margin-top: 10px;
}
.h-c{
    line-height: 60px;
}
.l-p {
    display: block;
}
